Aeronautics is the science involved with the study, design, and manufacturing of
airflight-capable machines, or the techniques of operating aircraft and rocketry
within the atmosphere. While the term—literally meaning "sailing the air"—originally
referred solely to the science of operating the aircraft, it has since been expanded
to include technology, business and other aspects related to aircraft.

One of the significant parts in aeronautics is a branch of physical science called
aerodynamics, which deals with the motion of air and the way that it interacts with
objects in motion, such as an aircraft. Aviation is a term sometimes used interchangeably
with aeronautics, although "aeronautics" includes lighter-than-air craft such as
airships, and includes ballistic vehicles while "aviation" does not.

Early aeronautics

The first mention of aeronautics in history was in the writings of ancient Egyptians
who described the flight of birds. It also finds mention in ancient China where
people were flying kites thousands of years ago. The medieval Islamic scientists
were not far behind, as they understood the actual mechanism of bird flight. Before
scientific investigation of aeronautics started, people started thinking of ways
to fly. In a Greek legend, Icarus and his father Daedalus built wings of feathers
and wax and flew out of a prison. Icarus flew too close to the sun, the wax melted,
and he fell in the sea and drowned. When people started to scientifically study
how to fly, people began to understand the basics of air and aerodynamics. Ibn Firnas
may have tried to fly in 8th century in Cordoba, Al-Andalus.

Roger Bacon and Leonardo da Vinci were some of the first modern Europeans to study
aeronautics. Leonardo studied the flight of birds in developing engineering schematics
for some of the earliest flying machines in the late fifteenth century AD. His schematics,
however, such as the Ornithopter ultimately failed as practical aircraft. The flapping
machines that he designed were either too small to generate sufficient lift, or
too heavy for a human to operate.

Although the ornithopter continues to be of interest to hobbyists, it was replaced
by the glider in the 19th century. Sir George Cayley was one of the most important
people in the history of aeronautics. Many consider him the first true scientific
aerial investigator and the first person to understand the underlying principles
and forces of flight.[3] A pioneer of aeronautical engineering,he is credited as
the first person to separate the forces of lift and drag which are in effect on
any flight vehicle,

Francesco Lana de Terzi, a 17th century Jesuit professor of physics and mathematics
from Brescia, Lombardy, has been referred to as the Father of Aeronautics.[6] In
his work Prodromo dell'Arte Maestra (1670) he proposes a lighter-than-air vessel
based on logical deductions from previous work ranging from Archimedes and Euclid
to his contemporaries Robert Boyle and Otto von Guericke.

Early aviation research

Many cultures have built devices that travel through the air, from the earliest
projectiles such as stones and spears.,[7][8] the boomerang in Australia, the hot
air Kongming lantern, and kites. There are early legends of human flight such as
the story of Icarus, and Jamshid in Persian myth, and later, somewhat more credible
claims of short-distance human flights appear, such as the flying automaton of Archytas
of Tarentum (428–347 BC), the winged flights of Abbas Ibn Firnas (810–887), Eilmer
of Malmesbury (11th century), and the hot-air Passarola of Bartolomeu Lourenço de
Gusmão (1685–1724). The modern age of aviation began with the first untethered human
lighter-than-air flight on November 21, 1783, in a hot air balloon designed by the
Montgolfier brothers. The practicality of balloons was limited because they could
only be controlled vertically. It was immediately recognized that a steerable, or
dirigible, balloon was required. Jean-Pierre Blanchard flew the first human-powered
dirigible in 1784 and crossed the English Channel in one in 1785.

In 1799 Sir George Cayley set forth the concept of the modern airplane as a fixed-wing
flying machine with separate systems for lift, propulsion, and control.[10][4] Early
dirigible developments included machine-powered propulsion (Henri Giffard, 1852),
rigid frames (David Schwarz, 1896), and improved speed and maneuverability (Alberto
Santos-Dumont, 1901)

Early aviation

While there are many competing claims for the earliest powered, heavier-than-air
flight, the most widely-accepted date is December 17, 1903 by the Wright brothers.
The Wright brothers were the first to fly in a powered and controlled aircraft.
Previous flights were gliders (control but no power) or free flight (power but no
control), but the Wright brothers combined both, setting the new standard in aviation
records. Following this, the widespread adoption of ailerons versus wing warping
made aircraft much easier to control, and only a decade later, at the start of World
War I, heavier-than-air powered aircraft had become practical for reconnaissance,
artillery spotting, and even attacks against ground positions.

Aircraft began to transport people and cargo as designs grew larger and more reliable.
In contrast to small non-rigid blimps, giant rigid airships became the first aircraft
to transport passengers and cargo over great distances. The best known aircraft
of this type were manufactured by the German Zeppelin company.

The most successful Zeppelin was the Graf Zeppelin. It flew over one million miles,
including an around-the-world flight in August 1929. However, the dominance of the
Zeppelins over the aeroplanes of that period, which had a range of only a few hundred
miles, was diminishing as aeroplane design advanced. The "Golden Age" of the airships
ended on May 6, 1937 when the Hindenburg caught fire, killing 36 people. Although
there have been periodic initiatives to revive their use, airships have seen only
niche application since that time.

Great progress was made in the field of aviation during the 1920s and 1930s, such
as Charles Lindbergh's solo transatlantic flight in 1927, and Charles Kingsford
Smith's transpacific flight the following year. One of the most successful designs
of this period was the Douglas DC-3, which became the first airliner that was profitable
carrying passengers exclusively, starting the modern era of passenger airline service.
By the beginning of World War II, many towns and cities had built space, and there
were numerous qualified pilots available. The war brought many innovations to aviation,
including the first jet aircraft and the first liquid-fueled rockets.

Modern aviation

After World War II, especially in North America, there was a boom in general aviation,
both private and commercial, as thousands of pilots were released from military
service and many inexpensive war-surplus transport and training aircraft became
available. Manufacturers such as Cessna, Piper, and Beechcraft expanded production
to provide light aircraft for the new middle-class market.

By the 1950s, the development of civil jets grew, beginning with the de Havilland
Comet, though the first widely-used passenger jet was the Boeing 707, because it
was much more economical than other planes at the time. At the same time, turboprop
propulsion began to appear for smaller commuter planes, making it possible to serve
small-volume routes in a much wider range of weather conditions.

Since the 1960s, composite airframes and quieter, more efficient engines have become
available, and Concorde provided supersonic passenger service for more than two
decades, but the most important lasting innovations have taken place in instrumentation
and control. The arrival of solid-state electronics, the Global Positioning System,
satellite communications, and increasingly small and powerful computers and LED
displays, have dramatically changed the cockpits of airliners and, increasingly,
of smaller aircraft as well. Pilots can navigate much more accurately and view terrain,
obstructions, and other nearby aircraft on a map or through synthetic vision, even
at night or in low visibility.

On June 21, 2004, Space Ship One became the first privately funded aircraft to make
a spaceflight, opening the possibility of an aviation market capable of leaving
the Earth's atmosphere. Meanwhile, flying prototypes of aircraft powered by alternative
fuels, such as ethanol, electricity, and even solar energy, are becoming more common
and may soon enter the mainstream, at least for light aircraft.

Rocketry

A rocket or rocket vehicle is a missile, spacecraft, aircraft or other vehicle which
obtains thrust from a rocket engine. In all rockets, the exhaust is formed entirely
from propellants carried within the rocket before use.[11] Rocket engines work by
action and reaction. Rocket engines push rockets forwards simply by throwing their
exhaust backwards extremely fast.

Rockets for military and recreational uses date back to at least 13th century China.[12]
Significant scientific, interplanetary and industrial use did not occur until the
20th century, when rocketry was the enabling technology of the Space Age, including
setting foot on the moon.

Rockets are used for fireworks, weaponry, ejection seats, launch vehicles for artificial
satellites, human spaceflight and exploration of other planets. While comparatively
inefficient for low speed use, they are very lightweight and powerful, capable of
generating large accelerations and of attaining extremely high speeds with reasonable
efficiency.

Chemical rockets are the most common type of rocket and they typically create their
exhaust by the combustion of rocket propellant. Chemical rockets store a large amount
of energy in an easily released form, and can be very dangerous. However, careful
design, testing, construction and use minimizes risks.

Aerospace

Aerospace comprises the atmosphere of Earth and surrounding space. Typically the
term is used to refer to the industry that researches, designs, manufactures, operates,
and maintains vehicles moving through air and space. Aerospace is a very diverse
field, with a multitude of commercial, industrial and military applications.

Aerospace is not the same as airspace, which is a term used to describe the physical
air space directly above a location on the ground. "Aerospace" can be understood
as the combination of aeronautics and astronautics.

View of the Earth's atmosphere and the Moon beyond.

Overview

In most industrial countries, the aerospace industry is a cooperation of public
and private industries. For example, several countries have a civilian space program
funded by the government through tax collection, such as NASA in the United States,
ESA in Europe, the Canadian Space Agency in Canada, Indian Space Research Organisation
and Hindustan Aeronautics Limited in India, JAXA in Japan, RKA in Russia, China
National Space Administration in China, SUPARCO in Pakistan, Iranian Space Agency
in Iran, and Korea Aerospace Research Institute (KARI) in South Korea.

Along with these public space programs, many companies produce technical tools and
components such as spaceships and satellites. Some known companies involved in space
programs include Boeing, EADS, Lockheed Martin, MacDonald Dettwiler and Northrop
Grumman. These companies are also involved in other areas of aerospace such as the
construction of aircraft.

History

Modern aerospace began with Sir George Cayley in 1799. Cayley proposed an aircraft
with a "fixed wing and a horizontal and vertical tail," defining characteristics
of the modern airplane.

The 19th century saw the creation of the Aeronautical Society of Great Britain,
the American Rocketry Society, and the Institute of Aeronautical Sciences, all of
which made aeronautics a more serious scientific discipline.[1]Airmen like Otto
Lilienthal, who introduced cambered airfoils in 1891, used gliders to analyze aerodynamic
forces.The Wright brothers were interested in Lilianthal's work and read several
of his publications.They also found inspiration in Octave Chanute, an airman and
the author of Progress in Flying Machines (1894).It was the preliminary work of
Cayley, Lilienthal, Chanute, and other early aerospace engineers that brought about
the first powered sustained flight at Kitty Hawk, North Carolina on December 17,
1903, by the Wright brothers.

War and science fiction inspired great minds like Konstantin Tsiolkovsky and Werner
von Braun to achieve flight beyond the atmosphere.

The launch of Sputnik 1 in 1957 started the Space Age, and on July 20th,1969 Apollo
11 achieved the first manned moon landing.In 1981, the space shuttle "Columbia"
launched, the start of regular manned access to orbital space. A sustained human
presence in orbital space started with "Mir" in 1986 and is continued by the "International
Space Station". Space commercialization and space tourism are more recent focuses
in aerospace.

The Future for Aerospace

We live in a world of tomorrow, and ironically, our technological capabilities are
far better than anything von Braun or any of the engineers of the 1950s could imagine.
For us to dream of settling the Moon or Mars is hardly a wild dream. It is clearly
possible, and doable both cheaper and in a much grander scale than anything imagined
half a century ago. It is time we did it. It is time we finally did what the better
dreams before us could only imagine, to have bold dreams, to be visionaries, to
try a grand new adventure.

It is time we went to the stars.

Aircraft maintenance

Aircraft maintenance is the overhaul, repair, inspection or modification of an aircraft
or aircraft component. Maintenance includes the installation or removal of a component
from an aircraft or aircraft subassembly, but does not include: Elementary work,
such as removing and replacing tires, inspection plates, spark plugs, checking cylinder
compression, etc.

• Servicing, such as refueling, washing windows. Any work done on an aircraft or
aircraft component as part of the manufacturing process, prior to issue of a certificate
of airworthiness or other certification document. Maintenance may include such tasks
as ensuring compliance with Airworthiness Directives or Service Bulletins.

Regulation of Aircraft Maintenance

Aircraft maintenance is highly regulated. There are various airworthiness authorities
around the world. The major airworthiness authorities include:

Field maintenance on a Cessna 172 being conducted
from a van used to carry tools and parts

Maintenance release

At the completion of any maintenance task a person authorized by the national airworthiness
authority signs a release stating that "The described maintenance has been performed
in accordance with the applicable airworthiness requirements." In the case of a
certified aircraft this may be an Aircraft Maintenance Engineer or Aircraft Maintenance
Technician, while for amateur-built aircraft this may be the owner or builder of
the aircraft.